Marylebone's period flats often feel like a run of separate rooms rather than one connected living space. GS Renovation opens them up across W1, from a single knock-through to a full kitchen-diner or a broken-plan layout with Crittall dividers. Over 30 years of Westminster structural work sit behind every opening we form.
Open-plan conversions in Marylebone flats
The good news in a Marylebone mansion flat is that many of the dividing walls are non-structural partitions, so a broken-plan or open layout is often more achievable than owners expect. Where the wall between kitchen and reception is only a partition, we can take it out and finish the space without a steel. Where it is load-bearing, we form a proper supported opening, and the layout options are much the same either way.
A structural engineer confirms which walls carry load before anything moves. For a load-bearing knock-through The engineer sizes the steel beam, seat it on padstones, prop the floor above, and demolish in staged sections so the opening is formed safely. Crittall-style glazed screens are a favourite in these high-ceilinged W1 rooms, letting you zone a kitchen-diner while keeping light flowing through, and they suit the period character of a mansion block beautifully.
Leasehold rules for Marylebone open-plan
Even where a wall is only a partition, your lease may still require the freeholder's consent to alter the flat's layout, and the managing agent will want to know what you are planning. If a steel is involved, the licence to alter and building-control certification both apply. Sound insulation matters too, because opening rooms up and laying new floors can change how noise carries to the flats next door and below in a close-built block.
This internal work does not need planning permission; it is governed by the Building Regulations, with Westminster City Council's building control signing off any structural opening. Planning would only apply to exterior changes on a listed or conservation-area building. We handle the freeholder licence, the agent liaison and the sign-off together, then carry out the work around the block's rules on hours and access, keeping communal lobbies and lifts clean throughout so life near the West End carries on.
- Ventilation and extraction planned for an open kitchen
- Rooflights and glazed roofs to bring light deep into the plan
- Openings formed in stages to keep the home usable
- Radiator relocation and underfloor heating in the new layout
- Steel beam installation to remove the dividing wall
Why Choose GS Renovation in Marylebone
For open-plan conversions in Marylebone, GS Renovation is one team from first survey to final skim. We tell you honestly which walls are partitions and which need a steel, size any beam with our engineer, secure the freeholder's licence and building-control sign-off, and fit Crittall screens neatly. Thirty years-plus in W1 mean the result is open, bright and properly certified.
- Structure and finishes delivered by one team on one programme
- Founder-led team with 30+ years of hands-on experience
- The house kept usable while the opening is formed in stages
- Registered in England, Companies House no. 14611254
- Fully insured, with cover in place on every site
- Paperwork and certificates handed over for when you sell